1 /*- 2 * Copyright (c) 2017 Colin Percival 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 #include <sys/param.h> 29 #include <sys/kernel.h> 30 #include <sys/linker.h> 31 #include <sys/malloc.h> 32 #include <sys/proc.h> 33 #include <sys/sbuf.h> 34 #include <sys/sysctl.h> 35 #include <sys/systm.h> 36 #include <sys/tslog.h> 37 38 #include <machine/atomic.h> 39 #include <machine/cpu.h> 40 41 #ifndef TSLOGSIZE 42 #define TSLOGSIZE 262144 43 #endif 44 45 static volatile long nrecs = 0; 46 static struct timestamp { 47 void * td; 48 int type; 49 const char * f; 50 const char * s; 51 uint64_t tsc; 52 } timestamps[TSLOGSIZE]; 53 54 void 55 tslog(void * td, int type, const char * f, const char * s) 56 { 57 uint64_t tsc = get_cyclecount(); 58 long pos; 59 60 /* A NULL thread is thread0 before curthread is set. */ 61 if (td == NULL) 62 td = &thread0; 63 64 /* Grab a slot. */ 65 pos = atomic_fetchadd_long(&nrecs, 1); 66 67 /* Store record. */ 68 if (pos < nitems(timestamps)) { 69 timestamps[pos].td = td; 70 timestamps[pos].type = type; 71 timestamps[pos].f = f; 72 timestamps[pos].s = s; 73 timestamps[pos].tsc = tsc; 74 } 75 } 76 77 static int 78 sysctl_debug_tslog(SYSCTL_HANDLER_ARGS) 79 { 80 int error; 81 struct sbuf *sb; 82 size_t i, limit; 83 caddr_t loader_tslog; 84 void * loader_tslog_buf; 85 size_t loader_tslog_len; 86 87 /* 88 * This code can race against the code in tslog() which stores 89 * records: Theoretically we could end up reading a record after 90 * its slots have been reserved but before it has been written. 91 * Since this code takes orders of magnitude longer to run than 92 * tslog() takes to write a record, it is highly unlikely that 93 * anyone will ever experience this race. 94 */ 95 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req); 96 97 /* Get data from the boot loader, if it provided any. */ 98 loader_tslog = preload_search_by_type("TSLOG data"); 99 if (loader_tslog != NULL) { 100 loader_tslog_buf = preload_fetch_addr(loader_tslog); 101 loader_tslog_len = preload_fetch_size(loader_tslog); 102 sbuf_bcat(sb, loader_tslog_buf, loader_tslog_len); 103 } 104 105 /* Add data logged within the kernel. */ 106 limit = MIN(nrecs, nitems(timestamps)); 107 for (i = 0; i < limit; i++) { 108 sbuf_printf(sb, "%p", timestamps[i].td); 109 sbuf_printf(sb, " %llu", 110 (unsigned long long)timestamps[i].tsc); 111 switch (timestamps[i].type) { 112 case TS_ENTER: 113 sbuf_printf(sb, " ENTER"); 114 break; 115 case TS_EXIT: 116 sbuf_printf(sb, " EXIT"); 117 break; 118 case TS_THREAD: 119 sbuf_printf(sb, " THREAD"); 120 break; 121 case TS_EVENT: 122 sbuf_printf(sb, " EVENT"); 123 break; 124 } 125 sbuf_printf(sb, " %s", timestamps[i].f ? timestamps[i].f : "(null)"); 126 if (timestamps[i].s) 127 sbuf_printf(sb, " %s\n", timestamps[i].s); 128 else 129 sbuf_printf(sb, "\n"); 130 } 131 error = sbuf_finish(sb); 132 sbuf_delete(sb); 133 return (error); 134 } 135 136 SYSCTL_PROC(_debug, OID_AUTO, tslog, 137 CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_SKIP, 138 0, 0, sysctl_debug_tslog, "", "Dump recorded event timestamps"); 139 140 MALLOC_DEFINE(M_TSLOGUSER, "tsloguser", "Strings used by userland tslog"); 141 static struct procdata { 142 pid_t ppid; 143 uint64_t tsc_forked; 144 uint64_t tsc_exited; 145 char * execname; 146 char * namei; 147 int reused; 148 } procs[PID_MAX + 1]; 149 150 void 151 tslog_user(pid_t pid, pid_t ppid, const char * execname, const char * namei) 152 { 153 uint64_t tsc = get_cyclecount(); 154 155 /* If we wrapped, do nothing. */ 156 if (procs[pid].reused) 157 return; 158 159 /* If we have a ppid, we're recording a fork. */ 160 if (ppid != (pid_t)(-1)) { 161 /* If we have a ppid already, we wrapped. */ 162 if (procs[pid].ppid) { 163 procs[pid].reused = 1; 164 return; 165 } 166 167 /* Fill in some fields. */ 168 procs[pid].ppid = ppid; 169 procs[pid].tsc_forked = tsc; 170 return; 171 } 172 173 /* If we have an execname, record it. */ 174 if (execname != NULL) { 175 if (procs[pid].execname != NULL) 176 free(procs[pid].execname, M_TSLOGUSER); 177 procs[pid].execname = strdup(execname, M_TSLOGUSER); 178 return; 179 } 180 181 /* Record the first namei for the process. */ 182 if (namei != NULL) { 183 if (procs[pid].namei == NULL) 184 procs[pid].namei = strdup(namei, M_TSLOGUSER); 185 return; 186 } 187 188 /* Otherwise we're recording an exit. */ 189 procs[pid].tsc_exited = tsc; 190 } 191 192 static int 193 sysctl_debug_tslog_user(SYSCTL_HANDLER_ARGS) 194 { 195 int error; 196 struct sbuf *sb; 197 pid_t pid; 198 199 sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req); 200 201 /* Export the data we logged. */ 202 for (pid = 0; pid <= PID_MAX; pid++) { 203 sbuf_printf(sb, "%zu", (size_t)pid); 204 sbuf_printf(sb, " %zu", (size_t)procs[pid].ppid); 205 sbuf_printf(sb, " %llu", 206 (unsigned long long)procs[pid].tsc_forked); 207 sbuf_printf(sb, " %llu", 208 (unsigned long long)procs[pid].tsc_exited); 209 sbuf_printf(sb, " \"%s\"", procs[pid].execname ? 210 procs[pid].execname : ""); 211 sbuf_printf(sb, " \"%s\"", procs[pid].namei ? 212 procs[pid].namei : ""); 213 sbuf_printf(sb, "\n"); 214 } 215 error = sbuf_finish(sb); 216 sbuf_delete(sb); 217 return (error); 218 } 219 220 SYSCTL_PROC(_debug, OID_AUTO, tslog_user, 221 CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE|CTLFLAG_SKIP, 222 0, 0, sysctl_debug_tslog_user, 223 "", "Dump recorded userland event timestamps"); 224